I have seen those tiny SD cards in the stores too.

They were created mainly for cell phones.
The ones I have seen also come with an adapter that will let you use them in your camera.
But.....adapters make me nervous....what if they get jammed in the camera?

You need the normal SD card for your Canon SD700.

The biggest manufacturer of SD cards is SanDisk.
But...most any brand will work fine.

Just don't buy memory cards on eBay.
Lots of reports of counterfeit cards being sold on eBay.

...
..
.